Asymmetric Supercapacitors Using 3D Nanoporous Carbon and Cobalt Oxide Electrodes Synthesized from a Single Metal-Organic Framework

作者：Salunkhe, Rahul R.; Tang, Jing; Kamachi, Yuichiro; Nakato, Teruyuki; Kim, Jung Ho^*; Yamauchi, Yusuke

来源：ACS Nano, 2015, 9(6): 6288-6296.

DOI：10.1021/acsnano.5b01790

• nanoporous materials
• coordination polymers
• metal-organic frameworks
• cobalt oxide
• carbon
• supercapacitors

Nanoporous carbon and nanoporous cobalt oxide (Co3O4) materials have been selectively prepared from a single metal organic framework (MOF) (zeolitic imidazolate framework, ZIF-67) by optimizing the annealing conditions. The resulting ZIF-derived carbon possesses highly graphitic walls and a high specific surface area of 350 m(2) g(-1), while the resulting ZIF-derived nanoporous Co3O4 possesses a high specific surface area of 148 m(2).g(-1) with much less carbon content (1.7 at%). When nanoporous carbon and nanoporous Co3O4 were tested as electrode materials for supercapacitor application, they showed high capacitance values (272 and 504 F.g(-1), respectively, at a scan rate of 5 mV.s(-1)). To further demonstrate the advantages of our ZIF-derived nanoporous materials, symmetric (SSCs) and asymmetric supercapacitors (ASCs) were also fabricated using nanoporous carbon and nanoporous Co3O4 electrodes. Improved capacitance performance was successfully realized for the AS( (Co3O4/carbon), better than those of the SSCs based on nanoporous carbon and nanoporous Co3O4 materials (i.e., carbon//carbon and Co3O4//Co3O4). The developed AS( with an optimal mass loading can be operated within a wide potential window of 0.0-1.6 V, which leads to a high specific energy of 36 W. h. kg(-1). More interestingly, this ASC also exhibits excellent rate capability (with the highest specific power of 8000 W. kg-1 at a specific energy of 15 W.h.kg(-1)) combined with long-term stability up to 2000 cycles.

• 出版日期2015-6